tumbling loaded rounds

Discussion in 'Vintage Topic Archive (Sept - 2009)' started by Silicon Wolverine, Dec 25, 2007.

  1. Silicon Wolverine

    Silicon Wolverine Well-Known Member

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    help settle an argument me and another guy are having. Is it OK to tumble loaded rounds for 5-15 min to get off any remaining case lube and make them shiny? he says yes, i say no.

    My side is the vibration could change the powder burn characteristics, static charge could set off a round, and it could kick up unhealthy amounts of lead residue.

    His side is that it says it is OK in most tumbler manuals, factory ammo producers do it, and any handloaders do it regularly.

    what your take on it? Anybody do this?

    SW
     
  2. I have never done it personally, but I don't see a problem with it. Most standard media won't build up enough of a static electrical charge to set off the powder in a case, so I think that you're safe there.

    As far as changing the powder burn characteristics, what do you mean by that?

    As for the lead, I don't think that would be much of an issue as most people load with FMJ rounds. If you're talking about tumbling 1000 rounds of 9mm that you loaded with 124 grain cast lead bullets, then yeah I could understand the concern.

    But, before I say yea or nay, please explain to me what you mean by the powder burn characteristics changing...
     

  3. Could it be that it may tumble the gunpowder enough to make it change into smaller flakes and this change the burn rate or something like that?
     
  4. Silicon Wolverine

    Silicon Wolverine Well-Known Member

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    thats exactly what i mean. espeecially using flake powder like red dot or blue dot. you could either rub off the coating on the powder or break it down into smaller pieces.

    SW
     
  5. How would that negatively affect the burn rate of the powder?

    You guys obviously understand more about the science of gunpowder itself, but I am not following you.
     
  6. Ari

    Ari Guest

    I wonder if there is a chance of static setting something off
     
  7. I haven't reloaded in over 15 years, but I did tumble loaded cartridges for a few minutes to remove lube with no problem. I guess if you tumbled them for a long period of time you could physically change the properties of the powder and alter its burn characteristics.

    As a note: I read of a case years ago where a rifle failed-KB- and the ammo was deemed the culprit. It seems the ammunition had been stored in a glove compartment for years in all weather and the pickup was a ranch truck that spent all of its time on unpaved roads. The conclusion was that years of vibration and expansion-contraction cycles from temperature change had reduced the propellant to a find powder. Its burning rate was increased and overpressure was the result. No, I won't try and find the article as it was written at least 20 years ago and is probably not available on the 'net.

    There-I really didn't help anything, did I? :roll:
     
  8. Primal its basically if the same gunpowder was formed into a small pellet, and also in flakes, they will burn at differnt speeds because of their size and compression differences. The different speeds of burning will cause different rates of combustion pressure build up.

    That is pretty well how I understand it.

    I know the 105 mm shells used pellets instead of flakes to make a different rate of burn and pressure.
     
  9. Gramps

    Gramps Guest

    If you are worried about that, ground the unit. All of my loaders are grounded and I have an area of steel shelving which is also grounded.
     
  10. Silicon Wolverine

    Silicon Wolverine Well-Known Member

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    i figured more on static discharge from the tumbling media to the metal cartridge case setting it off.

    SW
     
  11. As far as the static, I doubt very seriously that you could tumble a case long enough to set it off... It's like getting a round to "cook off" in the glove box of your car/truck during the summertime. It's possible, but extremely unlikely...
     
  12. Silicon Wolverine

    Silicon Wolverine Well-Known Member

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    i looked over on the reload board and they talked about tumbled rounds picking up 50-150 FPS across a chrono vs untumbled rounds. thoughts?

    SW
     
  13. I have heard the same thing about tumbling live rounds but the general consensus is that tumbling for a short bit isn't going to cause any harm but will remove lube.

    I have read a few threds where someone loaded up a few 9mm with red dot and tumbled them for 24 hours. At the end, the powder was still pretty much the same as it was before tumbling.

    That is HEARSAY and not to be taking but with a grain of salt, but you should research it on other reloading boards.

    But tumbling for a short bit to remove lube? Should not be a problem.

    I think that static discharge would be the least of your worries if there are any worries.
     
  14. It's not like you can't just touch the round to a grounded piece of equipment or shelving like Gramps suggested.
     
  15. Ari

    Ari Guest

    There are powders that change quick from being shaken. I was talking about this with an old time reloader a few weeks ago. Really he was telling me. He said that some powder will change just from getting shaken on the firing line line running in place before you shoot (something we used to do in the Military) I do not think I will be tumbling any live ammo...
     
  16. You can bet that any tumbling is done before the powder is put in with any military gun team or sniper grade ammo. I would be very surprised to hear different.
     
  17. Ari

    Ari Guest

    ya and I have no idea what powders are hurt by shaking
     
  18. I dont think it makes any difference to normal people like us, but there might be something to it for people that expect to put bullets in a quarter at 1000 yds, who knows?
     
  19. Gramps

    Gramps Guest

    I have never done this nor have I ever had any poor results from and residual case lube. I do not load rifle ammo and can not speak about that. I am at an age where I have decided the KISS principle is about the best way to approach most things.

    I load mid-range only loads for 9,38,45. I tumble deprimed cases and manually inspect each and every case. I don`t have dirty primer pockets nor do my inspection lights allow me to miss any media packed in a case.

    When I am ready to load I already know the condition of the cases are very good and they are clean. I use very little case lube with my Dillon 550B. I know my loaders are grounded so there will be no static problems with powder. I use the same powder with all loads with 1 exception only. I have a powder despenser on each different caliber block so the settings don`t change. I see no reason to tumble my loaded rounds ever. I generally have a less than 10 fps difference from fastest to slowest rounds and weight check mabe too often. I make changes slowly and carefully.

    If you are going to do anything with loaded rounds please be very careful. Find a shooter with a crono. Actually imo no loader should be without one. Load some rounds and tumble 1/2. Mark clearly and shoot over the crono. If there is a velocity difference, there is a pressure difference. Be consistant. Put a timer on the tumbler so you don`t accidently run them for an excessive time, (mostly for those with live in partners or other distractions). Either tumble them all or none.

    Loading is safe and adds great enjoyment to our sport if done properly. If not, you can cause serious harm to yourself and others.

    Gramps lecture out!
     
  20. while it is possible in theory to get a change in burn characteristics through a short tumble the effects would be minimal at best. I read a thread on this issue on a reloading forum and the general consensus was that its fine. I do it from time to time but not always.